Month: July 2022

Allium schoenoprasum, which is commonly known as chive, is a perennial plant that is used as a popular seasoning and is cultivated globally . Phytochemical analyses of A. schoenoprasum extracts revealed that its water extract contains flflavonoid compounds, glycosides, and saponins while the methanol and ethyl acetate extracts contain alkaloids, flavonoids, glycosides, and saponins . Chive leaves have great medicinal values, such as positive effects on the circulatory system by reducing blood pressure and antimicrobial effects . Chive leaf infusions, often rich in potassium, are used for treatment of kidney stone disease by dissolving calcium oxalate in kidneys . Kucekova et al. demonstrated that chive flower extract obtained by solid-liquid extraction have a great effect on human keratinocyte cell line by decreasing cell proliferation, perhaps, due to their phenolic compounds. It is worth-mentioning that chives may contain many of the bio-active phenolic compounds such as gallic acid, coumaric acid, ferulic acid, and rutin that are commonly found in other Allium spp. Hence, the objective of this study was to assess plant growth of chive and secondary metabolites of chive leaves and roots following cultivation in a plant growth medium inoculated with conidia of an endophytic entomopathogenic fungus under greenhouse conditions. This is the first study on the experimental inoculation of chive with an endophytic fungus, vertical hydroponic nft system and its subsequent effects on plant growth and production of secondary metabolites.An indigenous B. bassiana strain that was previously isolated from a soil sample collected from the Cape Winelands in South Africa was used in this study. This strain was identified using molecular and morphological techniques as described in Moloinyane and Nchu .

The strain is being maintained at Cape Peninsula University of Technology in Bellville, South Africa. The fungus was cultivated on half-strength potato dextrose agar ; 0.02 g/L of ampicillin , and 0.04 g/L streptomycin in 9 cm and 14 cm diameters petri dishes. Fungal cultures were incubated at 25 C in the dark for four weeks. Using a spatula, mature four-week-old B. bassiana conidia obtained from PDA plates were transferred to 2 L glass bottles containing sterile 0.01% Tween 80 and sterile water. Bottles were capped, mixed by shaking for 5 min and by using a magnetic stirrer to homogenous conidial suspensions. The conidia inoculum concentration was enumerated using a haemocytometer and observed with a light microscope at 400X magnification. In order to obtain the desired concentration , the volume of sterile 0.01% Tween was increased or conidia were added to the glass bottle. This was followed by 10-fold serial dilutions to obtain lower concentrations of conidial inoculum suspensions; 1 104 , 1 103 conidia mL 1 . A conidial germination test to determine conidial viability was carried out according to the method described by Inglis et al. and high spore germination of over 90% was obtained.Chive seedlings, were purchased from Stodels Nurseries Ltd in Bellville, Western Cape Province, South Africa. Plants were maintained in the greenhouse at Cape Peninsula University of Technology in Bellville, South Africa at 23–25 C, 60%–80% RH and 13/11 natural light/dark regime. Individual chive plants were separated from a clump and one plant was transplanted to each 10 cm diameter pot containing a substrate mixture of one-third of river sand, one-third of vermiculite, and one-third of perlite by volume. The substrate materials were sterilized using 1% sodium hypochlorite for 1h before rinsing with sterile distilled water. The plants were fed with water soluble, formulated hydroponic fertilizer, Nutrifeed . The fertilizer was dissolved in sterile distilled water at a concentration of 10 g/5 L and 100 mL of the mixture was added to each plant once a week. Each plant was watered with 100 mL reverse osmosis water once a week.Leaf length from the soil surface to the top of the highest leaf and leaf number of each plant were measured weekly for three weeks.

Leaf length increment was calculated as the difference between leaf length at weeks one and three and percentage growth was calculated as follows: 100 x the leaf length increment divided by week one leaf length. Similarly, leaf number was counted and leaf number increment and % increase were calculated. At the end of the experiment, three weeks post fungal inoculation, root length and fresh weights of plants were recorded.Dry weights of the plants were determined by placing plants in paper bags in a drying oven at 35 C for 7 days.To determine fungal colonization of leaf tissue, three sections of leaf as well as root sections were collected from each plant soon after harvesting. The excised material was surface sterilized by first dipping in 70% ethanol for 3 s and then rinsing in sterile distilled water for 1 min. Thereafter, the sterile leaf and root sections were placed on solid half-strength PDA, incubated in the dark at 25 C, and were checked for outgrowth of B. bassiana in root and leaf tissues under stereo microscope after one and two weeks. efficiency of surface sterilization was evaluated by placing drops of the previously used 70% ethanol and distilled water for surface sterilization on plates containing solid half-strength PDA, and then incubated and checked for fungal outgrowth.The spectroscopic method described by Fadhil and Reza was used to determine total alkaloids in the plant extracts. Briefly, 100 mg of the chive leaf and root materials were extracted separately with 10 mL of aqueous ethanol for 2 h, centrifuged and the supernatant was used in the assay. Two milliliters of the extract supernatant and atropine standard solutions were mixed with 5 mL sodium phosphate buffer and 12 mL bromocresol green solution. Thereafter, 12 mL of chloroform was added to the solution and the solution was mixed vigorously using a vortex mixer. The absorbance at 417 nm was determined and the concentration of mg atropine equivalent per g dry weight in the sample using a standard curve of atropine was calculated. The total polyphenol content of the aqueous ethanol extracts of dried leaf and root dried materials of the chives were determined by the FolinCiocalteu method . The method of Swain and Hills was adapted for the plate reader.

Using a 96-well microplate, 25 μL of the sample was mixed with 125 μL Folin-Ciocalteu reagent and diluted 1:10 with distilled water. After 5 min, 100 μL aqueous Na2CO3 was added to the well. The plates were incubated for 2 h at room temperature before the absorbance was read at 765 nm using a Multiskan plate reader . The standard curve was prepared using 0, 20, 50, 100, 250 and 500 mg/L gallic acid in 10% ethanol and the results were expressed as mg gallic acid equivalents per g dry weight . The flavonol content of the aqueous ethanol extracts of dried leaf and root materials of the chives were determined using quercetin 0, 5, 10, 20, 40, and 80 mg/L in 95% ethanol as standard. In the sample wells, 12.5 μL of the crude aqueous extracts were mixed with 12.5 μL 0.1% HCl in 95% ethanol, and 225 μL 2% HCl and incubated for 30 min at room temperature. The absorbance was read at 360 nm, at a temperature of 25 C . The results were expressed as mg quercetin equivalent per g dry weight .The B. bassiana isolate used in the present study was able to endophytically colonize chive plants. The re-isolation of the fungus from chive leaf samples showed that the fungus was systemic, i.e., inoculum was transferred from the growth medium to the leaves. This is the first record of successful experimental inoculation and colonization of B. bassiana in chives. Previous studies have reported the colonization of B. bassiana in other plant species with different inoculation methods . Inoculation with B. bassiana did not improve the growth of chives over the control treatment . In fact, the control plants had slightly higher biomass and root growth compared to the treated plants. These results differ from those reported in previous studies, which showed that B. bassiana promotes plant growth of cassava , faba bean and cotton . However, Lewis et al. reported no significant difference in the growth of maize plants exposed to seed treatments with B. bassiana and the corresponding control treatment. Jaber and Enkerli reported inconsistent endophyte-induced plant growth promotion across sampling dates following foliar inoculation of faba bean plants with B. bassiana , B. brongniartii and M. brunneum . The root lengths varied significantly among treatments, and the shortest length was observed in plants exposed to the highest concentration of fungal treatment, which may suggest that fungus might have had a negative effect on root length. In a more recent study, B. bassiana inoculation had a positive influence on plant growth parameters including root length of common beans .

Nevertheless, the colonization of plant tissues by fungal endophytes can be influenced by many factors, such as inoculation method, species and fungal strain . Fungal endophytes might affect the nutrient cycle and uptake of nutrients from the soil by plants . In this study, chemical analysis revealed that the leaves and roots of both B. bassiana-exposed and unexposed chive contained polyphenols, nft hydroponic system alkaloids and flavonols, and also that these secondary metabolites were significantly more concentrated in the leaves than in the roots. Chives and other Allium species, such as onion and garlic contain polyphenols, alkaloids, flavonoids, glycosides and organosulfur . Furthermore, higher alkaloid content was detected in the leaves of plants inoculated with B. bassiana than in the control treated plants . In a previous study, which involved the same fungal strain used in this study, drenching potted grapevine plants with its conidial suspension induced higher production of anti-insect volatile compounds including Naphthalene in the fungus-exposed plants compared to the control . The better yield of alkaloids in fungus-treated plants could be due to the synthesis of secondary metabolites by fungus in the plant tissues . Also, endophytes can potentially induce host plants to accumulate secondary metabolites . Zhang et al. reviewed a wide range of bio-active alkaloids that are produced by endophytic fungi. Lozano-Tovar et al. reported that B. bassiana produce secondary metabolites that can induce anti-fungal activity. B. bassiana produces several biological active metabolites of the class of alkaloids such as tennelin, bassianin, pyridovericin, and pyridomacrolidin .

In the current study, since the specific alkaloid compounds were not detected, it is not possible to establish with certainty whether the higher total alkaloid content detected in the fungus-treated plants in this study was due to the direct production of alkaloids by B. bassiana or the fungus physiologically influenced the plant cells to produce more alkaloids. It is worth mentioning that fungal endophytes can produce mycotoxins in their host that are potentially harmful to livestock and humans . In conclusion, this study demonstrated that endophytic entomopathogenic fungi could be used to improve the yield of alkaloids in medicinal plants. In order to further understand the influence of fungal endophytes on plant production of bio-active compounds, future studies involving detailed phytochemical elucidation of the bio-active constituents of fungus-treated plants are warranted.The accumulation of biosynthesised secondary metabolites in plants could enhance the value of plant-based medicinal materials . However, the physiological and morphological processes in plants are affected by ambient environmental factors. Water, for example, is an essential resource for plant growth and survival, and its availability influences plant physiological processes including biosynthesis of secondary metabolites and enzyme activities.Water has many essential roles in plants: it is used for translocation and distribution of nutrients and metabolites, it maintains rigidity of plant organs, it is a medium for chemical reactions, and it is an essential component of the photosynthetic process . Water deficit is the most important limiting factor of plant growth .Water deficits can affect photosynthesis through stomata closure and decreased CO2 diffusion to the chloroplast . Drought stress is also associated with the enhancement of accumulation of many classes of natural products in plants, such as terpenes, phenols, alkaloids and glucosinolates.Leaves of water-stressed Ctenanthe setosa tended to accumulate more carbohydrates of low molecular weight and phenolic acids .

They are smaller than baby greens and they are harvested later than sprouts. Due to their immaturity,they tend to have concentrated flavors, tender textures, vibrant color, and densely-packed nutrients. Various micro-greens, such as broccoli, kale, celery, opal basil,and red beet, are available in the market. Because of their potent  flavors and appealing sensory qualities,in the past few years,micro-greens have gained popularity and are often used by high-end chefs for garnishing soups and sandwiches. Their functional benefits have also drawn attention from nutrition researchers and have opened the door for use in the field of nutrition and health. This functionality is attributed to their high content of vitamins and minerals, as well as other bio-active compounds. It has been reported that many species of micro-greens are more saturated with micro-nutrients than the adult versions of the same plants. For instance, micro-greens have shown to be high in vitamins or their precursors, including carotenoids, ascorbic acid, to copherols and tocotrienols, phylloquinone and folate. Other phytochemicals found to be high in micro-greens include chlorophyll, phenolic compounds, anthocyanins, and glucosinolates. Results from Huang et al. showed that red cabbage micro-greens reduced high-fat diet induced weight gain and significantly lowered circulating LDL levels as well as expression of hepatic inflammatory cytokines in mice fed a high-fat diet.

Polyphenols, a class of phenolic compounds, were indicated to be a major contributor of the aforementioned effects of red cabbage micro-greens, partially owing to their antioxidant and anti-inflammation properties. Phenolic compounds, also seem to have an influence on sensory qualities of micro-greens. Xiao et al. reported that the total phenolic concentration was strongly correlated with the overall eating quality and several aspects of sensory qualities,ebb flow table including intensity of astringency, sourness, bitterness, and sweetness of micro-greens. Nowadays, products of micro-greens are available to consumers in both chain grocery stores and local farms. The growth environments and harvesting methods, however, are quite different. Farms grow micro-greens in soil or hydroponically. On the other hand, commercial micro-greens are usually hydroponically grown, which increases the productivity of micro-greens but may compromise their nutritional and sensory quality. In addition, micro-greens purchased from local farms are usually fresher than those from grocery stores due to shorter transportation time, which may further affect the nutrition and sensory properties of the plants. In spite of the increase of research on micro-greens, no study has evaluated the nutritional and sensory qualities of these specialty vegetables grown differently or from different sources. Such information is important for consumers in purchasing or for health professionals in conducting research or giving dietary advice. Therefore, the main objective of this study was to investigate the nutritional qualities and sensory properties of micro-greens grown and harvested in a commercial setting versus a local farm setting. The nutritional analysis will focus on chlorophyll content, phenolic compounds content, vitamin C content, and antioxidant capacity, which are known to contribute to the health benefits or sensory attributes of micro-greens. Since broccoli micro-greens is the only species available to researchers in both local grocery stores and local farms, it was selected for the comparison in nutritional and sensory qualities.

In addition, six other micro-greens that available in local farms were also analyzed for nutritional quality. We hypothesized that micro-greens grown in soil in a farm setting would possess higher nutritional qualities and produce better sensory properties as compared to those grown hydroponically and those from a commercial source.Commercial broccoli micro-greens samples which were hydroponically grown, were purchased from the Fresh Marketin Tuscaloosa, Alabama. These samples were designated as CH in this research. Farm grown broccoli micro-greens samples were purchased from the Alabama micro-greens . To elucidate the effects of growth environment on the qualities of micro-greens, micro-greens samples both grown in soil and hydroponics were obtained from the Alabama micro-greens. Six other micro-greens, including amaranth, kale, kohlrabi, pea, spicy broccoli, and wasabi, were also purchased from the Alabama micro-greens. The commercial micro-greens were packaged in plastic clamshell containers with unknown harvest date, while the farm samples were harvested on the same day of delivery and packaged in paper clamshell containers. Samples were used for laboratory analysis on the day of purchase and stored at 4 ◦C for the sensory study during following three days. The optical images of the three broccoli micro-greens samples are shown in Fig. 1.The sensory study was conducted on campus at the University of Alabama to evaluate the sensory qualities of micro-greens samples. Data collection was carried out in the student center during weekday lunch time . Participants were recruited by being asked whether they were interested in evaluating micro-greens and completing a survey. After being explained with the purpose of the study and showed the consent form, participants were provided the three samples of broccoli micro-greens in a random order, each in a small cup, for testing. Information about the source and growth conditions of the samples was blind to participants. Participants were asked to observe, smell, and taste each sample and evaluate their liking of smell, appearance, taste, and overall liking in a 7 Likert scale from very poor to excellent .

Participants were asked to drink water between samples. Upon completion of the survey, participants received a $3 Amazon gift card as an incentive. The study procedure and survey questionnaire were reviewed and approved by the Institutional Review Board at the University of Alabama.As shown in Fig. 2A, broccoli micro-greens samples from the local farm had significantly higher TCC than that from the commercial source . The TCC of hydroponically grown samples from the local farm was higher than that of the soil grown samples, but the difference did not reach statistical significance. Chlorophyll is a green pigment found in most plants and is essential for photosynthesis. A higher concentration of chlorophyll might indicate the production of more energy nutrients in the plants. Chlorophyll cannot be synthesized by animal tissues and must be obtained from plant foods. Recently, chlorophyll and chlorophyll-rich diets have been reported to play roles as cancer-preventive agent attributed to the ability of chlorophyll to form complexes with specific carcinogens, as well as its antioxidant and antimutagenic properties. Some other preventive or therapeutic properties of chlorophyll were also reported in literature, such as stimulating immune system, detoxifification of the liver, and normalizing blood pressure. Although more research is needed to elucidate the mechanisms under these functions of chlorophyll, it could be a valuable dietary compound for human nutrition and health. It was reported that mature broccoli contains about 0.02 mg/g of TCC, while the results showed that TCC in farm grown broccoli micro-greens was about 15 times higher. The TCC in those farm grown broccoli micro-greens was also higher than that of many other species of mature vegetables, such as celery, lettuce, and artichoke. The incorporation of these micro-greens in the diet can be a promising way to provide the health-beneficial chlorophyll and warrants more investigation. As compared to the high level of chlorophyll in farm grown broccoli micro-greens, commercial samples had a much lower TCC. Several factors might contribute to this difference.

The commercial samples might have been harvested before the development of the cotyledon leaves, where chlorophyll accumulates. The plant does not require light for the first few days of growth. The chlorophyll might also be degraded due to long supply chain and storage time of the commercial samples, deteriorating the freshness of the vegetable. The TCC could affect sensory quality of the micro-greens, especially their appearance and the impression of freshness.Results in Fig. 2B showed that there was no significant difference in the TPC between commercial and local farm samples. Furthermore, whether it was soil grown or hydroponically grown did not affect the TPC of the samples from the local farm. Phenolic compounds are a large class of plant secondary metabolites that comprise an aromatic ring with one or more hydroxyl substituents. These compounds are important for the quality of plants and are strongly associated with the flavor properties of vegetables, such as taste and color. For instance, phenolic compounds, e.g., tannins and phenolic acids, contribute to the astringency taste, i.e., the drying, puckering, and shrinking sensation in the oral cavity. Some phenolic compounds are colorless, while some others show various colors. Phenolic compounds show numerous bio-active properties, hydroponic grow table most well-known of which are their antioxidant and anti-inflammatory activities. Furthermore, a number of phenolic compounds demonstrate inhibitory effect on the activity of enzymes to digest starch in gastrointestinal tract, e.g., amylase and glucosidase, indicating a potential of these compounds in improving glucose homeostasis and metabolic conditions. The average TPC in broccoli micro-greens samples in this study was in the range from 10.71 to 11.88 mg/g. It is about 10 times higher than the TPC in a lot of species of mature vegetables, including broccoli, brussels sprout, and kailan, which are known to be excellent sources of phenolic compounds. Therefore, these micro-greens can be regarded as great sources of this class of phytochemicals. Future research is needed to analyze the profiles of specific phenolic compounds in micro-greens as well as their in vivo bioavailability, and to explore their beneficial effects in human health. Our results indicated that different growing and harvesting conditions did not affect the TPC of the micro-greens. The TPC of plants depends on the balance between its synthesis and oxidation. Phenolic compounds are produced through the phenylpropanoid metabolic pathway, which starts with the reaction of l-phenylalanine converted to trans-cinnamic acid, and other phenolics are produced via subsequent reactions. As antioxidants, phenolic compounds can be oxidized to quinone under oxidative stress. It was previously reported that light exposure or different packaging methods did not affect the TPC of radish micro-greens. Future research on the effects of growth environment, harvesting condition, and/or post-harvest interventions on the synthetic or oxidation pathway of phenolic compounds in plants will provide insights into the key factors that determine the TPC level of micro-greens.

Results on VCC indicated that broccoli micro-greens samples grown in soil from the local farm possessed significantly higher VCC than hydroponically grown ones from the farm and the commercial ones also grown hydroponically. Vitamin C is a co-factor required by many enzymatic reactions and a critical antioxidant. Previous studies showed that higher circulating vitamin C concentrations are associated with lower risks of hypertension, coronary heart disease, and stroke. Mature raw broccoli, known as an excellent source of vitamin C, contains an average of 0.89 mg/g of total ascorbic acid according to the USDA National Nutrient Database for Standard Reference. Mature spinach, one of the most commonly consumed leaf vegetable in the United States, has about 0.28 mg/g of total ascorbic acid. The VCC of our micro-greens broccoli samples is in the range of 0.33–0.56 mg/g. Worth to note is that the VCC measured in this study is the content of free ascorbic acid so the total ascorbic acid content would be higher.Therefore,micro-greens broccoli, especially the soil-grown ones from the local farm, can be regarded as good sources of vitamin C. Comparing VCC in vegetables grown in soil and hydroponically has created mixed results. For instance, a study by Treftz et al. found significantly higher ascorbic acid content in soil grown raspberries yet lower in soil grown strawberries, compared with their hydroponically grown counterparts. Buchanan et al. reported significantly higher total ascorbic acid content in three of the four hydroponically grown lettuce varieties than their soil grown versions, while the fourth one showed higher but non-significantly total ascorbic acid content. Although not fully understood, vitamin C is synthesized in plants as a response to oxidative stresses and through the l-galactose pathway using mannose or galactose. Therefore, the growth conditions, including nutrition in soil and hydroponic growing media, and environmental stresses may all impact vitamin C biosynthesis in micro-greens and result in the VCC difference in this study.Similar to the results of TPC, no significant difference was observed in the TAC of micro-greens samples from different sources and grown conditions . It has been well established that the consumption of vegetables is inversely associated with morbidity and mortality from chronic diseases and antioxidants play a significant role in the beneficial effects.

The lettuce cultured using the 2-fold ozonetreated sludge dilution solution showed significantly higher contents of chlorophyll, soluble sugar and Vc. The 2-fold ozone-treated sludge dilution solution improved the quality of hydroponic lettuce compared to the modified Hoagland nutrient solution used traditionally. It was also observed that unsuitable concentrations of ozone-treated domestic sludge dilution solution could inhibit lettuce growth. High sludge concentrations inhibited lettuce growth and at low sludge concentrations the nutrition provided was insufficient to satisfy the lettuce growth demand . The leaf number, plant height, fresh weight and dry weight in the lettuce cultured by the modified Hoagland nutrient solution were significantly higher than those cultured by any of the ozone-treated sludge dilution solutions. While the nitrate content in the lettuces cultured using the 1-, 2-, 3-, and 4-fold ozone-treated sludge dilution solutions were 34.3, 53.93, 55.34, and 68.60% lower than that in the modified Hoagland nutrient solution treatment, respectively, although the chlorophyll, soluble sugar and Vc contents increased. The various physiological indexes of lettuce were not independent and there was a certain relationship between them . As shown in Table 3, nitrate content had a significant or extremely significant correlation with leaf number, plant height and dry weight, and the correlation coefficient were 0.99, 0.86, 0.87, respectively. The result indicated that the nitrate content would increase with the leaf number, plant height and dry weight increasing. Thus, the leaf number, plant height and dry weight could be appraisal indexes of nitrate content. So, the nitrate content could be controlled within the scope of the security by the leaf number, plant height and dry weight.

And dry weight had a significant or extremely significant correlation with leaf number, plant height and root length, with the correlation coefficient of 0.89, 1.00, and 0.90, respectively. This was consistent with others reports . But the correlation for chlorophyll or soluble sugar content with other physiological indexes was not significant. Additinally, Vc had a significant correlation with leaf number. Some researches showed that the significant correlation among physiological indexes and quantitative trait loci  of corresponding physiological indexes may exist chain effect . Therefore, vertical farming racks the correlation among physiological indexes could be understood further by the correlation analysis among physiological indexes. The results could provide basic theory for genetic analysis of lettuce stress resistance in the future. The ozone-treated domestic sludge dilution solutions investigated in this study were thought to be an efficient liquid fertilizer substitute. Here, improvements in terms of physiological, biochemical and nutritional characteristics and safety in the lettuce growth process were observed. Before the sludge was treated by ozone, the number of fecal E. coli bacteria was measured. The results showed that the number of the feces in the sludge before ozone treating ismore than 1×105 L–1, which was measured with the most probable number  method, while the number of the feces in the modified Hoagland nutrient solution is zero. And the fecal E. coli was not detected in the 1-, 2-, 3-, and 4-fold ozone-treated sludge dilution solutions after ozone treated for 120 min, so ozone treatment showed strong bactericidal ability, which was beneficial to the effective control of pathogenic microorganisms. But heavy metal distribution in the sludge solution and lettuce cultivated with sludge must be studied in subsequent research. And further studies will also be performed on food safety.

Using ozone treated sludge dilution solution as fertilizer in hydroponic systems has the potential to outperform traditional fertilizers and to cut costs for growers, however, further research is necessary.It is evident from this study that increased accumulation of bio-active compounds, antioxidant properties and mineral composition can be achieved without compromising the yield by selecting less N sensitive varieties that can use N effectively. N application generally improved leaf area and attributed increased chlorophyll content due to the effective use of photosynthetically active radiation . However, the morphological response of the green lettuce varieties to different N supply rates differed from the reports of Mahlangu et al.  where, Lollo Bionda Lobi leafy lettuce grown in non-circulating hydroponic system  failed to show any increase in fresh weight although the form of N source was NH4 NO3 . In this study, fresh weight in the green varieties showed strong correlations with increasing N supply . However, discrepancies in results could be due to the type of growing system used or it can also be due to the genotype. In red lettuce varieties, photosynthetically produced carbon molecules are used more for the production of phenolic compounds than for the use of plant growth and fresh weight . This relates to the C/N shift theory that shows a shift to carbon based metabolites under N deficiency for the biosynthesis of phenolic acids and flavonoids . The reports of Becker et al.  further confirmed that the activity of phenylalanine ammonia-lyase that is responsible for the biosynthesis of polyphenol propanoids are higher at lower N concentrations, which further explains the observed increased phenolic acids  and flavonoids  and lower fresh leaf weight in var. Multired 4 in this study. Slight divergence in the trends were observed with the biosynthesis of phenolic acids in green varieties  with respect to N application rates in this study and the reports of Becker et al. . The lettuce genotypic differences could have attributed to these observed differences.

Increasing N application rates were shown to reduce phenolic acids and flavonoids in butter head lettuce cv. Egery . However in this study the response to increasing N supply with regards to the accumulation of different phenolic acids and flavonoids composition differed . N supply affects leaf chlorophyll content  and in this study N application rates between 90 to 120 mg L–1 were sufficient to maintain the chlorophyll content to carry out photosynthesis effectively in both green cultivars . This observation coincides with the findings of Mahlangu et al.  on the green lettuce cultivar Lollo Bionda Lobi grown in a non-circulating hydroponics system where 100 to 120 mg N L–1 was reported to be sufficient to maintain photosynthesis. However in cultivar Lollo Bionda Lobi, the relationship model between the applied N rates and the chlorophyll content fitted linearly  whereas in Mulitigreen 1 and Multigreen 3, they showed a polynomial model . The observed discrepancies in chlorophyll content could be due to the lettuce genotypic differences. Increased rates of N applications have been reported to reduce the ascorbic acid content in different fruit and vegetable crops . On the contrary, Chiesa et al.  reported that high N  increased ascorbic acid content in lettuce. Variation in accumulation of ascorbic acid content with respect to different rates of N applications varied with the findings of Mahlangu et al.  where the ascorbic acid concentration was higher at 100 to 120 mg N L–1. In this study, the highest ascorbic acid content was obtained at 60 mg L–1 in both green and red varieties  and as shown by Mahlangu et al.  it declined with increasing rates of N application. The observed divergences with regards to the N application rates and ascorbic acid content in lettuce can be explained due to the type of N source and application methods. Type of fertilizers such as ammonium nitrate  or urea  was shown to increase the ascorbic acid content compared with ammonium sulphate . Abd El-Rehem and Abd El-Baky  demonstrated that the use of ammonium nitrate reduced the ascorbic acid content with higher application rates. IM and FNB  recommended daily intake  for an adult male and female is 90 and 75 mg of ascorbic acid. It is evident in this study that 100 g of Multired 4 provides 17 mg of ascorbic acid at 60 mg N L–1 and similarly 100 g of Multigreen 1 and Multgreen 3 contained 14 and 15.5 mg of ascorbic acid, respectively.

Phenolic acids, vertical rack system flavonoids and ascorbic acid are known as antioxidants and play a major role in human nutrition. Stefanelli et al.  reported that the changes in total phenol content and the antioxidant power  revealed similar trend with increased rates of N applications and that the highest FRAP activity and total phenolic content was attained at 400 mg N L–1. Heimler et al.  established a positive correlation between total phenolic content and antioxidant capacity in 5 out of 10 lettuce cultivars. The trend in antioxidant activity in this study differed from the findings of Mahlangu et al. , which showed higher activities at 120 mg L–1. In this study in all three cultivars the antioxidant power  and capacity  were higher at lower N concentrations  and decreased with higher rates of N application.Differences in nitrate accumulation between the green lettuce and red lettuce varieties were noted in this study and a similar observation was reported by Becker et al. . There is discrepancy between the findings of this study and the reports of Becker et al.  with regard to increasing nitrate content in the leaves with increasing rate of N application. Becker et al.  stated that the nitrate residue did not increase steadily with increasing N concentration in the nutrient solution. Permitted nitrate content for greenhouse lettuce is set at 4 500 mg kg−1 of fresh weight when grown from 1 October to 31 March and at 3 000 mg kg−1 from 1 April to 30 September by the European Community . Although the nitrate levels in the leaves were calculated on a dry weight basis in this study, the contents were much lower than the levels set by the European Community. It can be recommended to use less N sensitive varieties to promote the production of phytochemicals and to reduce accumulation of nitrates in a controlled production system.

Reports of Stefanelli et al.  stated that Ca increased while B, Mg, Mn, and Zn significantly decreased with increasing N application rates. In this study N application rates helped to improve the mineral composition  in the leaves and different accumulation trends were noted with respect to the different cultivars with the red cultivar responding well. Petropoulos et al.  showed the influence of N application on Mn and Zn in lettuce leaves . However, in this study, N application influenced the accumulation of Mn in Multigreen 3 . An increase in minerals especially Fe, and Mn that are an important source of micro elements in lettuce will add value by enhancing the nutritional value in the food chain. Rice is the foremost staple food in Asia, feeds more than 60% of the population in China and constitutes up to 40% of the total national grain production . At present, there is an urgent need to shift rice production toward mechanized farming . Mechanical transplantation is an emerging rice planting method in China and represents an important opportunity for scaled, simplified, commercialized, and modernized development . Mechanical transplantation has several advantages, such as high and stable yields and high efficiency , and has developed rapidly in China in recent years; the use of mechanical transplantation will guide the future direction of national agricultural production to solve the problems concerning severe shortages in the rural labor force and to achieve full mechanization of rice cultivation. However, traditional rice seedling cultivation methods for mechanical transplantation are time consuming and laborious, and collecting topsoil for the boxes can disrupt soil structure and subsequently reduce crop yields. All of these factors limit the development of mechanical transplantation of rice in China. The use of hydroponically grown long-mat rice seedlings  represents a novel seedling cultivation method that reduces labor costs and improves efficiency . This method presents two main features: first, non-woven cloth is used as the medium instead of soil, and the seedlings are cultivated hydroponically; second, nursery seedling boxes that are 3 to 6 m in length are used rather than traditional small rectangular boxes . The grain yield and economic benefit of HLMS were equivalent or superior to those of traditional nutritive soil methods because of the robust seedling quality, better transplantation quality and higher dry matter accumulation during late growth of the former ; in addition, the root entwining force of HLMS is enhanced, resulting in significantly increased flexibility of seedling age and enabling high-yielding and -efficiency rice production .

For blended DAP and KNO3 , both reverse fluxes of potassium and nitrate were similar regardless of the FS tested, but smaller than with KNO3 alone. Therefore, it is hypothesized that the Js of K+ and NO3− are more dependent on DS than FS composition. However, it is worth mentioning that when using blended salts, nitrate reverse fluxes were even lower with Na+ in FS than when using only DI water  due to lower ion exchange. Thus, the presence more than the type of salt in the FS influenced the Js of nitrate ions. The obtained results show the complexity of ion interactions because the tested DS ions  behaved differently and were influenced, to different degrees, by both the presence of salts in FS and the DS composition. Forward fluxes  were minimal for all ions except for Na+ in tests with DAP and blended salts in DS, with Jsf ranging from 2.1 to 2.9 mmol m− 2 .h− 1 . As indicated by Hancock and Cath , feed solutes with larger hydrated radii , had better FO membrane rejection than monovalent ions . High sodium fluxes  are commonly reported , and in this study its presence influenced ammonium reverse fluxes. This is because Na + has higher diffusivity than Mg2+ and therefore its transport to the DS facilitates the ammonium transport to FS and vice versa . The percentage of mass of ion passage from FS to DS  showed higher Na+ passages with the pair of monovalent ions , because of the retarded sodium diffusion due to the divalent SO42− presence in the case of Na2SO4 in the FS . Similarly, lower anion  passages were experienced in presence of the divalent Mg2+ . These results point out the importance of FS composition for the performance of the FO process. Concerning draw solutes, divalent ions from FS showed lower forward fluxes, and thus the final FS and DS were less contaminated with ions from the opposite solution when divalent ions were present on both sides of the membrane. Fig. 6 indicates the distribution of solutes in FS and DS at the end of the tests.

A high percentage of draw solutes passed to the feed side, resulting in almost 100% fertilizer losses to FS in some cases . Such observations are of utmost importance as they jeopardize the interest of the FDFO concept. This reinforces the fact that KNO3 cannot be used alone as DS for fertigation. Comparatively,hydroponic bucket using DAP or blended fertilizers reduced the losses, which however were still very high for ammonium, nitrate and potassium in most cases as soon as salts were present in the feed solution. Ideally, osmotic equilibrium should be achieved by an equal EC between original FS and DS solutes without nutrient losses, and not because of large reverse flux of DS solutes to FS, limiting the DS dilution. However, the obtained Js and nutrient losses were very high, osmotic equilibrium was reached, and water fluxes decreased as a consequence of the salinity buildup in FS caused by the reverse fluxes of DS ions. Existing studies are controversial since some of them point out that the solute fluxes from DS to FS are not influenced by the presence of salts in FS , while others indicate the opposite . In this study, while the presence of salts in FS did not influence PO43− behavior, it did clearly influence both Js and losses of NH4+. Although the influence of salts in FS was not clear in terms of reverse fluxes of K+ and NO3− , Fig. 6 shows that it strongly influenced the passage of K+ and NO3− ions to the FS. Adequate nitrogen and potassium dilution for direct hydroponics application was achieved in some tests with magnesium ions in FS . For the rest of the cases, due to the high reverse fluxes, nitrogen and potassium concentrations were below the target ranges. In contrast, phosphate reverse fluxes, as well as mass dilution were minimal, and phosphate concentrations in the final DS were well above desired concentrations and toxicity levels. Therefore, the presence of salts in FS plays a fundamental role in the final concentrations of NPK in DS. Additionally, one of the main problems of sodium diffusion in FDFO is its final concentration in the DS, since the DS is intended to be used as a nutrient solution for direct application in hydroponics. Sodium concentrations over 50 mg.L− 1 are toxic for the plants .

Average sodium concentrations in the final DS of tests with NaCl and Na2SO4 in FS were above the level of toxicity . These results indicate that Na+ forward fluxes may compromise the quality of the final DS and the general efficiency of the FDFO process. Nanotechnology is now considered one of the most promising applied disciplines and involves the manipulations of materials at the atomic level and the manufacture and assembly of metal, semimetal, and non-metal nanoparticles and their various industrial and agricultural applications . However, all NPs manufactured are ultimately released into the environment and eventually reach cultivable soils. Accordingly, NPs are considered an emerging class of contaminants . ZnO-NPs and CuO-NPs are among the most studied nano metal-oxides in terms of their environmental impacts, but their effects on cereal crops like maize have not been well researched. For example, Cu-based pesticides account for a sizeable proportion of the global demand  , and research interest had shifted towards the use of CuO-NPs rather than Cu bulk or salt-based pesticides , due to their nano-specific properties such as higher S/V ratios, surface energies, and bioreactivities. CuO-NPs are also used as catalysts and in sensors, batteries, solar energy converters, textiles, optics, and microelectronics . Similarly, ZnO-NPs have potential applications in the manufacture of solar cells, sensors, piezoelectric devices, cosmetics, and medical devices . Given the potential usage of CuO-NPs, it is inevitable that as a result of discharge, soil and water become major nanoparticle sinks. Therefore, NPs pose potential issues concerning the metabolic activities, structures, and functions of plants and for human health due to the consumption of edible plants and the contamination of water . Plants have large surface areas and are potential ecological receptors for NPs, and thus, NPs pose the risk of adversely affecting crop production .

Recent studies have shown that CuO and ZnO NPs are accumulated by some terrestrial plants at high levels and cause phytotoxic effects, which may be due to the uptakes of Cu2+ or CuO-NPs. Furthermore, the addition of maize root exudates during the co-cultivation of maize seedlings in the presence of 25 mg L− 1 of CuO NPs for 7 days increased CuO-NP accumulation and hampered seedling growth . On the other hand, ZnO-NPs at 100 mg L− 1 alleviated Zn deficiency in maize seedlings after adsorption on seed endosperm and internalization . The majority of studies on maize/ZnO-NP interactions have been performed on agar media up to the seedling stage, and in one such study, ZnO-NPs were found to reduce seedling root growth by 51% at 1000 mg L− 1 . Nonetheless, we considered that further comparative studies were required to investigate in more detail the response of maize plants to different concentrations of ZnO-NPs and CuO-NPs in different growth media. Metal-oxide based NPs penetrate plant cells by endocytosis or other passive/facilitated transport routes and are then either accumulated at locations near entry points or are transported to other plant organs, and their accumulations and interactions with cellular components damage plant anatomies and physiologies . Furthermore, it has been reported the uptakes, translocations, and bioaccumulations of NPs in plants depend on physicochemical features, genotypes, and plant anatomies . On the other hand, free metal ions such as Cu2+ and Zn2+ are known to adversely impact crop plants, and due to their solubilities in water and deposition in soils to pose an increasing environmental challenge.Maize was selected for the present study due to its economic importance. Maize is an edible flowering plant of the family Poaceae and is the third most-produced cereal crop after rice and wheat .

It is considered a human staple food and animal feed in most developing countries and is rich in proteins, carbohydrates, essential minerals, fat, iron, and vitamins. Furthermore, maize has also been reported to interact with some metal-based NPs such as TiO2-  and Fe3O4-NPs . Little is known about the comparative impacts of nano and bulk ZnO or CuO or Zn2+ and Cu2+ ions on maize cultivation in different media, in which the effects of nano, bulk, and ionic species may be differentially influenced by their different mobilities and interactions with maize plants. Although the use of soil-less media is desirable for the toxicity assessment of NPs on crop plants, stackable planters soil-based approaches are more relevant because soil effects can alter material activities. Thus, the uncontrolled disposal and improper recycling of CuO-NPs and ZnO-NPs in the environment is likely to increase plant exposure, which in turn is likely to affect their accumulation kinetics and other ecosystem trophic levels. Therefore, the objective of the study was to assess the phytotoxic impacts of nano and bulk ZnO and CuO and Zn2+ and Cu2+ on maize using plate assay, hydroponic conditions and soil environment. The depths of ZnO- and CuO-NP penetrations were detected and visualized by SEM, EDX, and elemental mapping analyses, and NPs aggregates and ultrastructures in maize root and leaf cells were examined by TEM. Accumulations of Zn and Cu from NPs, bulk materials, and ions in maize roots and metal translocations to upper ground parts were investigated by ICP-MS. The presence of chemical functional groups and possible alterations were observed by FT-IR of lipids, proteins, and carbohydrates in roots and shoots. Root cells were also analyzed by flow cytometric analysis to detect the apoptotic growth phase . In addition, we assessed the impacts of NPs, bulk materials, and ions on phosphorus accumulation, soluble protein and chlorophyll production, and on the inductions of proline, oxidative radicals, and antioxidant enzymes. Few reports have been issued on the adverse impacts of metal-oxide NPs on the growths and biochemical attributes of maize plants , but few are available on the toxic effects of ZnO-NPs and CuO-NPs on physiological and morphological parameters of maize grown in different media or compared these effects with those of bulk ZnO or CuO or Zn2+ or Cu2+. Similar to the current study, ZnO-NPs at 400 mg l− 1 reduced maize seed germination maximally by 53%, but Zn2+ had no negative impact .

In an earlier study, CuO-NPs at 100 mg L− 1 significantly inhibited root elongation of maize seedlings but CuO-bulk did not . Because of their increased uptakes and consequent accumulations, soil adsorbed ZnO- and CuO-NPs interact with many cellular components, and thus, interfere with the metabolic activities of maize and cause cellular damage that might reduce crop production. To check the adsorption of NPs to soil constituents, SEM-EDX scanning of soil before and after adding CuO-NPs  showed the presence of a prominent Cu signal in the EDX spectrum that was not detected in non-treated control soil . Reduced water flow and limited root hydraulic conductivity caused by the physical adsorption of NPs of ZnO or CuO into the nano-sized pores of maize roots restrict growth , and this reduction in water availability inhibits maize leaf growth and transpiration by physically blocking apoplastic flow. Frequency of occurrence of smaller sized particle aggregates after addition of ZnO and CuO NPs  in soil was higher than that of non-treated soil  which suggests the availability of added NPs and their role in physical blockage of maize root pores . Furthermore, resulting reductions in the supplies of water/nutrients and the higher intracellular concentrations of Zn and Cu could disturb root and shoot transcriptomes and suppress the expressions of genes that participate in primary, cellular, and secondary metabolic processes . At lower concentrations, Zn and Cu species improved the biological parameters . This could be due the fact that Zn when present at below threshold levels in plants, acts as a co-factor for many essential enzymes of plants.

Higher rates of N application have been associated with discolouration during storage in cabbage and potato. Berard  demonstrated the influence of higher N application rates on the incidence and severity of black midrib in cold storage in the susceptible cultivar Safe keeper. Furthermore, electrolyte leakage in the leaf tissue was reduced at lower N application rate and electrolyte leakage and change in membrane structure increased at higher N application rates . But, according to the previous authors, these results were not consistent during the two years of investigation . However, in the current study, red and green lettuce varieties showed different trends in their browning response related to the chromaticity b* value with respect to the N application rates . The application of higher than recommended N rates in gravel film technique affected the fresh cut visual quality and coincides with the previous findings of Poulsen et al. and Bonasia et al. . In Multigreen 1, the higher N application rates for a shorter time showed lower browning . Therefore, it is evident from this study that the response to preharvest N application rates on browning depends on the variety. Wounding increases the PAL activity . Physiological attributes related to quality attributes and storage life of minimally processed lettuce coincided with increasing concentration of predominantly phenolic acids in different fresh cuts of lettuce cultivars. Increase in specific phenolic acid concentration differed according to the N application in different cultivars in this study . Furthermore, the decrease in phenolic acids and increasing PPO is likely to explain the browning or deep blush brown colour in red Multired 4 during storage with higher N application rates . The reduction in b* value related to the onset of browning in the fresh cuts of Mulitired 4 and Multigreen 3 were minimised by lower preharvest N application rates  due to fairly higher concentrations of ascorbic acid . However, Luna et al.  reported that the ascorbic acid concentrations are higher in red lettuce cultivars compared to the green cultivars.

The higher ascorbic acid concentrations in Multired 4 could probably have controlled the browning and maintained the higher b* value . Multired 4 showed improved shelf life and overall quality due to the higher concentration of phenolic compounds and lower PPO activity than the two green lettuce cultivars . Reducing trend in dicaffeoyltartaric acid concentration was reported during post harvest storage at 5°C and 85% RH . However, a divergence in observation with regards to the increase in dicaffeoyltartaric acid content in Multigreen 1 at similar storage conditions could deny its participation as a substrate for browning mechanism.Hence,hydroponic nft system the import of goods is necessary to meet the food demand of urban citizens, which has caused an increased dependency on the global food production and supply system. Such a reliance on external inputs represents a vulnerability when major political or economic disruptions occur, and it can often be the leading cause of such instabilities. The inequality in food distribution represents an additional risk, worsen by the increasing urban poverty. Adding on to the local challenges for food provisioning, the global food supply chain is also vulnerable to big-scale changes. In fact, climate change will put food security at risk on several levels, for example by reducing yields and land suitability, and by increasing frequency and severity of extreme weather events. Satisfying the demand of fertilizers is another environmental challenge of food production, given that mineral fertilizers are a non-renewable resource that is being consumed at an increasing rate. In addition to being vulnerable to disruptions, the food system is also responsible of environmental degradation; considering the environmental impacts generated by the final consumptions of the European Union, the production and distribution of foodstuff accounts for 30% of the impacts on climate change, 33% of the impacts on ecotoxicity and 60% of the impacts on eutrophication. Urban agriculture has been proposed as a practice to respond to the challenges presented above, and produce positive environmental, economic and social effects, such as shortening the food supply chain, reducing the emissions of greenhouse gasses, microclimate improvement, improved water management, improved diet-related health, and stress reduction. Smit and Nasr pointed out that urban agriculture could promote the development of a circular economy by closing ecological loops using wastewater and organic solid waste as inputs. However, urban agriculture is not a homogeneous practice, and includes, among the others, small commercial farms, community-supported agriculture, community gardens, rooftop gardens or greenhouses, hydroponic and aquaponics farms and indoor agriculture. Mougeot proposed to categorize UA based on types of economic activity, products, location, area used, production system, production scale, and product destination. Given this variability, a case-by-case evaluation is needed to show if and in what conditions UA can deliver positive impacts and can replace conventional agriculture.

Urban agriculture has been studied from a life cycle perspective, reporting different results that show that UA is not a less impacting production system per se. For example, Kulak et al. calculated that up to 34 t CO2eq ha-1 a-1 could be avoided by substituting conventional agricultural products with vegetables from community gardens in the UK. On the other hand, for Goldstein et al. urban agriculture in northern climates performs worse than its conventional counterpart, mainly because of its high energy requirement and/or low yields. Sanyé-Mengual et al. evaluated a rooftop greenhouse production in Barcelona: their results show that the UA system had a lower impact on the environment, but that crop efficiency was determinant for the performance of the cultivation. This case study analyses, from an environmental perspective, a vertical hydroponic urban farm called “La Petite Ferme du Grand Lyon” and based in Lyon , using Life Cycle Assessment. The pilot farm is run by the private company ReFarmers and produces leafy greens and herbs that are sold directly to restaurants and citizens.This work’s goal is to evaluate the environmental performance of a high-yield vertical hydroponic farm, and to compare it to conventional agriculture. The analysis shows whether and to what extent this type of hydroponic is able to produce vegetables with a lower environmental impact than soil-based conventional agriculture. By showing if urban agriculture can compete with conventional vegetable production, this study highlights the strong and weak points of urban hydroponic production in temperate continental climates, and therefore supports the improvement and development of sustainable urban food supply systems. Urban agriculture is, in this case, a supplementary source of vegetables; therefore, the capacity of urban hydroponic agriculture to fulfil the entire food requirement of European cities is outside of the scope of this study. The modelling framework applied is attributional LCA. According to the ILCD Handbook we identified our case study as a Situation A “micro-level, product or process-related decision support study”. In fact, by having a small market share, the farm’s products can impact on the market solely to a limited extent, generating only small-scale consequences [22].We performed a cradle-to-gate analysis considering the cultivation phase and the transport of the products to the retailers. Figure 1 shows the boundaries of the system.The end-of-life of the capital goods was selected depending on the material: steel, aluminium and iron parts are recycled, as well as PVC and PE plastic components; the other plastic materials, which cannot be recycled due to their composition, are sent to incineration. We had to exclude the process of pest control through insect release; the insects are not bred in the farm, and no literature data could be found about the breeding process of parasitoids and the related inputs. The fixation of CO2 by the plants was omitted because the gas is expected to be released in the near future as a biogenic emission of carbon dioxide. Moreover, as we compare the same amount of produced lettuce, the uptake of carbon dioxide is the same for both types of cultivation. Since the fertilizers are not lost through the soil, but remain available to the plants thanks to the recirculation of the water, we assumed the fertilizers emissions to be zero.

For conventional agriculture, we considered two scenarios: the production and delivery of lettuce grown in heated greenhouses  and the production and delivery of open field cultivated lettuce ; both the scenarios were derived from the Ecoinvent database. In all the three scenarios, the packaging of the vegetables has not been included. This choice is justified by the fact that the impact of packaging has been showed to be relatively low [24].The Life Cycle Inventory  of scenario S1  consists of data provided by the farmers, covering four months of production in 2016. The annual production was extrapolated considering the seasonal variation of some inputs, such as the water demand. Moreover, we took into account that the production stopped for 1.5 months in winter due to low temperatures. The losses of production in the farm are indirectly accounted for, since the farmers reported the yields as production ready to be sold, i.e. the losses has been already subtracted. The farm covers an area of around 325 m2 , of which  only 18% were used for the plant cultivation. The seedlings are not produced in the farm but bought from a local organic company; since no direct data were available, we refer to the seedling production process from Stössel et al.. We assumed no heating is required, since the plant variety are selected according to the season. A neighbour farm manages the transport to the retailers of the vegetables from the hydroponic farm, together with their production; a mass allocation was performed to distribute the impacts of this process, and a car trip of 20 km per week was estimated. No losses of products are assumed in this phase, due to the length and frequency of the trip.As an overview, the urban vertical hydroponic production  shows the best performance in the categories of marine eutrophication and agricultural land occupation. For climate change, freshwater eutrophication, freshwater ecotoxicity and fossil depletion, the impact is higher than on-field conventional agriculture . Anyway, in all cases except for water depletion the performance of S1 is visibly better than the production of lettuce in heated greenhouses . These results are explained by taking into consideration the characteristics of the different systems. The vertical hydroponic farm requires more capital goods than the other types of cultivations, since it does not rely on soil substrate, but needs vertical plastic structures and a recirculating irrigation system, which requires electricity . For climate change, nft channel the consumption of electricity contributes for two thirds to the impact in scenario S1, while in scenario S3 the production and use of fertilizers are the main responsible of greenhouse gas  emissions. Whereas these two scenarios differ for only 0.10 kg CO2eq, when lettuce is grown in heated greenhouses , it is responsible of the emission of 7.08 kg CO2eq per every kg of lettuce that reaches the supermarket.

By recirculating water and avoiding losses for infiltration, scenario S1 has a water consumption seven times lower than greenhouse conventional production, and around four times lower than on-field cultivation, that benefits from rain events . In Mediterranean climates, such as Greece, the water demand per kg of lettuce production reaches 83 litres, fourteen times higher than in vertical hydroponics. However, the irrigation system requires a constant water flow guaranteed by a pumping system, which consumes electricity. The impact of electricity depends on how this electricity is produced; given the location of the farm, we considered the French energy mix, of which more than 70% is nuclear energy. The production of nuclear energy has a high requirement of cooling-water, which explains why scenario S1 has a worse impact on water depletion, even if it has a smaller direct water consumption. Table 3. Results of the Life Cycle Impact Assessment of 1 kg of lettuce grown in the three scenarios: vertical hydroponic production , heated greenhouse production and on-field cultivation . The results are normalised with respect to the yields in Table 2. The consumption of electricity for irrigation is among the main contributing processes for all the impact categories, but is less impacting than the consumption of heat of the conventional greenhouse scenario. In facts, scenario S2 has the worst performance  in every category.

As mentioned in the previous section, the weather data in each station are interpolated to determine the temperature for the entire country. In terms of yield per area, the hydroponic production of tomato is found to be greater than open-field production. Hydro-ponic greenhouse tomato production is estimated with a yield of 195.3 kg/m2/y, whilst the yield in an open field is projected at 3.23 kg/m2/harvest. It is assumed that the duration of harvest for tomato is every 2 months during the year and that there are zero harvests during the summer period . Consequently, the estimated yield in an open field is estimated to be 9.69 kg/m2/y. The high yields of hydroponics production of tomato result from the controlled environmental conditions maintained within the hydroponic greenhouse, which allow for continuous production all year round. The advantages of hydroponic production will vary depending on the operational parameters under which the crop is grown and is not unique nor limited to tomato alone. Similarly, water utilization in a hydroponic greenhouse and open field production of tomato in Qatar is compared for various seasons. The results summarized in Table 8 indicate that less water demand is required in hydroponic production in comparison to open field production. Therefore, it is considered as a more efficient farming method, due to the fact that the hydroponic system delivers the water more resourcefully, with a larger percentage of the water going to plant evapotranspiration . The tomato crop evapotranspiration per season for open-field agriculture and hydroponic greenhouse as a growing method is summarized in Table 9. The result demonstrates that hydroponic is more efficient than open field by 5%, where it saves around 4000 mm/day/season in the summer.

Due to the controlled nature of the climate within a greenhouse, the amount of crop water lost by evaporation and transpiration processes would be reduced. All greenhouses have the capability of reducing evapotranspiration through increasing humidity and entrapping moisture level, flood tray physically blocking wind, and reducing the solar radiation by filtering out some direct sunlight that reaches the plants; this is due to the greenhouse’s protective covering that performs all of these three functions. Results for energy consumption per each component in a hydroponic greenhouse for tomato production in Qatar are illustrated in Appendix C. Due to the availability of 40 ha for the production area in Agrico farm, it requires more energy for cooling in comparison to other three farms. Moreover, the energy for supplemental artificial lighting is assumed to be constant for all seasons, as it set to the optimal value required in tomato production. Furthermore, the results demonstrate that most of the energy consumption in the hydroponic greenhouse is due to the cooling loads. This is primarily due to the fact that the greenhouse is located in AlKhor, in the North of Qatar, an area which can have average temperatures of 40 °C in the summer and 20 °C in the winter. However, if greenhouses are to be located in more reasonable climates that are closer to the greenhouse set point temperature, they would experience a lower energy requirement. The other use of energy for the hydroponic greenhouse is for supplemental artificial lighting, which is used to maximize crop yield and maintain consistent production year-round. Some systems use supplemental lighting to create a 24-h photoperiod, especially during the first few days of plant growth, whereas others may use supplemental lighting for only a few hours a day . In addition, small and low-output systems may not use artificial lighting at all. However, in this study, it is assumed that the maximum yield is desired . In addition, the other energy components that affect total energy consumption in the hydroponic greenhouse include the energy used to pump groundwater from approximately 40 m depth for irrigation purposes, and the energy used to distillate brackish water using reverse osmosis technology.

The energy consumed by RO plants is calculated only for SAIC farm due to the onsite availability of two RO plants with a capacity of 370 and 700 m3/day, and by considering a value between 0.5 to 3 kWh/m3 for specific energy consumption . Furthermore, one of the objectives of the study is to observe how changes in technology or production methods can affect the utilization of water and energy in farms. Accordingly, water and energy consumption are also estimated for the four farms assuming an open field for tomato production. The overall energy consumption in both open field and hydroponic greenhouse are summarized in Table 10. The main observation demonstrated from the assessments is that the node is affected by seasonality, growing method and size of the production area. Different seasons will have different water and energy consumption, this is especially noticeable in an open field scenario, where in summer, open field farms will suffer from high temperatures leading to high evapotranspiration and hence higher water demands. Furthermore, as stated previously, depending on the production method  used for tomato, a large variation within water and energy consumption exists. The production area also influences the overall energy and water demands, where Agrico is the largest farm in comparison to the others with an area of 40 ha with corresponding hydroponic energy needs of 5133.3 kJ/kg/year. Although SAIC farm has a smaller area of 2.8 ha, it still consumes large quantities of energy in the hydroponic greenhouse due to the two onsite RO plants.Increasing consumption of natural resources and energies, global environmental problems have appeared. Nowadays, many people face major environmental issues. Especially water problem is spread around the world . Approximately 2.4 billion people are in strict water-stressed condition . The deterioration of water environment has been accompanied by the factors concerning health hazard and agricultural production. On the other hand, two-thirds of fresh water in the world is irrigation water for agriculture to provide foods. Because of these reasons, food production is strongly close to water issues. Hence, preservation of water quality and economy is important ranging from human life to agriculture. According to these various studies, the assurance of high water quality is serious issue to be solved.

In agriculture, advanced technique against environment stress for high quality vegetable production has been discussed by many researchers , and they mentioned that it is more important to control nutrient solution in water circulation systems. The pH in nutrient solution is related to the plant growth and nutrient components in hydroponics. The nutrient solution used in hydroponics has been related to pH, electrical conductivity , ion concentration, temperature  and additional chemical compounds. Hydroponic system for agricultural production has several advantages such as it can use unsuitable area, independence of environmental conditions and easy controlled root systems. Moreover, plant factories adopt hydroponic system because the plant factories need cultivation systems to control plant growth and produce high quality. In this study, we focused on nutrient solution especially water structure. Water is a unique liquid in our world and has a highly structured liquid . Recently, many water analyses were carried out to investigate water structure to know hydrogen bonding and hydration effect. For example electrolytes solution is assessed through viscosity , thermally stimulated current method  and 1 H NMR spectroscopy . One of dynamic status in water expresses viscosity.Therefore, viscosity as one of the fundamental macro parameters in a solution was evaluated for water status such as ion concentration, temperature and pressure . The absorption of water is essential for the growth of most plants because they lose large amount of water daily. Plant cells constitute approximately 90 % of water. Therefore, water state surround root systems of crops is important in agricultural production. However, the relation in water structure including the state of hydrogen bound formed water molecules and physiological function of plant growth has not been clarified. As the viscosities decreased in the nutrient solution for plant growth, recent studies have suggested that the uptake of ions and water by plant roots would be easier . Other research has demonstrated that the thermally stimulated current method, the method of water analysis, has carried out for hydroponic system . For growth of plants, ebb and flow tray the using water to prepare the nutrient solution is limited by water quality . Therefore, quality and structure of water for agricultural use is expected to continue improving.

However, water structures are difficult to apply hydroponic system due to complex relationship between roots and waters. For this purpose in this study, nutrient solutions in various concentrations of ions were compared concerning viscosity. In addition, viscosity of nutrient solution was measured not only in different concentration but in different temperature. The data obtained from this experiment will be to control nutrient solution in hydroponic system for production of high quality vegetable and stable production.Evaluation of water structure influenced by ion concentration is complex phenomenon such as ion-water molecular interaction and states of hydrogen bond in water. In general, viscosity is one of general value which are information regarding ion-solvent interaction and fundamental state deciding dynamics property of water structure making or breaking characteristics. Therefore, the viscosity is one of the fundamental parameters deciding dynamic property in the water. In this experiment, viscosity was focused and measured with a digital rotary viscometer as adapted measurement of low viscosity. LCP  was used for spindle, and revolution speed of the spindle was 100 rpm. The samples of nutrient solutions were taken 18 mL into sample adaptation by a pipette. The viscosities were recorded during 7 min except 3 min after starting an analysis. Averages of viscosities were calculated using last 2 min . Because water temperature influences the viscosity of solution, water temperatures of all samples were measured before measuring viscosities by thermocouple. The water temperatures were controlled by a low-temp thermostatic water bath  circulated surround sample adapter. The average of all plots was recorded and all samples were carried out in triplicate. For comparison of viscosities in different temperature, nutrient solution fixed its concentration and temperature only changed over 5-35 o C.In relation between viscosity and EC value, the viscosity significantly increased with the increase in the EC value . Regression analyses showed that there were significantly positive correlations between viscosities and electrical conductivities . In general, this tendency of increasing viscosity explains that main cause was the different concentration of ions due to structure making effect. This result suggested that nutrient solution changed its viscosity during cultivation period. Without automatic managing ions concentration, nutrient solutions during cultivation period increase or decrease at end of growth period. According to previous study, hydration of inorganic ions can assort into two groups, one is “positive hydration” and the other is “negative hydration”. These groups have different behaviors in water. “Positive hydration” forms ordering water structure by bivalent, trivalent ions and alkali ions. On the other hands, “negative hydration” behaves structure-breaking on the water structure by univalent ions . Concentrations of positive hydration ions, especially magnesium and calcium, dissolved nutrient solution. This result indicated that nutrient solution was observed higher viscosity due to shift concerning ion concentrations. Antibiotics are widely used in medical treatment, veterinary medicine, aquaculture and other areas.

The global annual consumption of antibiotics in agriculture, aquaculture, and livestock husbandry reached 100,000–200,000 tons  and the amount of antibiotics used worldwide is expected to reach 106,000 tons in 2030 . However, 30–90% of antibiotics are excreted in urine and feces as parent compounds or metabolites . Therefore, antibiotics are constantly released into the environment. Existing studies have shown that antibiotics are widely found in water environments , posing a great threat to humans, animals and aquatic habitats . When Iris pseudacorus and Typha were exposed to 2 mg/L of furosemide, the plants have a positive growth rate at the end of 21 days experiment . Concentrations of fluoroquinolone antibiotics , particularly levofloxacin , in the upper ng/L to lower μg/L range are frequently detected in wastewater . LOFL is widely applied as an antidysenteric and antibacterial agent and for the treatment of pneumonia and immunodeficiency virus . Existing research has shown that the environmental fate of FQs is influenced by photodegradation, adsorption, and biodegradation.

The quantity of P present in the control streams is much bigger than the one in the struvite streams, with the former irrigating and leaching 2.07 and 1.41 g of P per plant for the entire crop cycle, respectively. The fact that the P leachates are one order of magnitude smaller when using struvite  could be related to the slow-release characteristic of struvite reported in the literature. A clear benefit of this finding is a decrease in both P depletion and freshwater eutrophication related to the leachates flow. Moreover, if the leachates of struvite treatments do not contain a large amount of P, it means that most of the struvite has been whether taken up by the plant or remains undissolved in the substrate. When comparing Figs. SM12 and SM18 of the Supplementary material, we can see that P release by struvite is highly dependent on the input water flow, represented in Figs. SM11 and SM17 for the validation and determination test, respectively. Because the volume of irrigated water was three times less in the determination test , the P observed in the leachates is less than in the validation test, considering the period where P was not supplied through mineral fertilizer in the validation test. Differences are observed within the struvite treatments in Fig. 4, highly dependent on the quantity of struvite that was applied at the beginning of the crop. Treatments S1 and S2.5 stopped emitting P in the leachates just 14 DAP, which could have triggered P deficiencies. On the other hand, treatments S15 and S20 were the only struvite treatments that did not stop emitting P to the leachates flow.Treatments S1 and S2.5 had lower yields than the control treatments, establishing a clear relationship between the yield and possible P deficiencies in these treatments. However, struvite remains undissolved in all treatments,mobile grow rack even though the production and the distribution of P among plant organs was different between treatments .

The fact that we have undissolved struvite even in treatments S1 and S2.5 shows that the limitation is not only related to the quantity of struvite available, but also its dissolution . While the struvite dissolution has been previously deemed to be due to the crystal granule size and placement previous literature fails to report the effect of the irrigated water flow. Previous experiment on the struvite dissolution in deionized water make clear that a greater dissolution can be ensured with greater temperature and stirring energy as well as an acidic pH reaching greater dissolutions close to the commercial fertilizers. On the other hand the volume of water flows added to the crop has not been regarded as a determining factor when granulated struvite is directly added to the substrate, especially in hydroponic production. The obtained results in the present work shed light on the effect of the incoming irrigation on the struvite dissolution as well as loss of P in the leachate. Because the volume of irrigated water was three times lower in the determination test, the P observed in the leachates is lower than in the validation test, considering the period where P was not supplied through mineral fertilizer. Moreover, there is a significant amount of P accumulated in the substrate bag at the end of the treatment in the control test. This stored P will be depleted if a successive crop is planted, since the small nursery plants will not benefit from all of it due to the lower needs of a smaller plant. With the addition of irrigation the accumulated nutrients in the perlite bag would eventually be moved to the leachates. By applying struvite this P is not stored and thus, not lost. Based on the findings of this study, a well-designed struvite crop cycle needs to take into account two essential parameters. First, the quantity of struvite, considering that the quantity that remains undissolved at the end of the crop can be used again for a successive cycle. Second, the irrigation management, considering that if we modify this variable to increase the dissolution of struvite granules, we would also be increasing the P in the leachates.

Moreover, since previous studies highlighted the effect of the surface area of the granules on the solubility of slow-release fertilizers , the size used in our study seems adequate for the balance between P supply and P lost through the leachates. Literature with higher sizes reported solubility problems that affected early plant development , while studies using lower sizes or powder do not report these problems . Additionally, the use of nursery plants is preferable since the struvite low dissolution has been reported to be a disadvantage when providing P to feed the transition from seeds to nursery plants . Struvite supply per plant should always be above 5 g for Phaseolus vulgaris, considering that more quantity of struvite would release more P into the leachates, but ensure that P is available for plants. On the other hand, we should also account for the nutritional value of the beans, considering the ultimate function is to produce yield. In this sense, P in the biomass was a variable where the control treatment had a better performance than struvite treatments. This uptake of similar P from struvite compared to soluble fertilizers has been previously reported by Ahmed et al. determining that different crops have a greater uptake of P while other have comparable or even lower growth. While Phaseolus vulgaris was not previously observed, a study with soybean was performed compared to the P uptake with triple superphosphate . The resulting crops show a similar uptake of both P sources by the plant with different quantities of P applied . The P uptake in Phaseolus vulgaris with the use of struvite compared to monopotassium phosphate can also be seen in previous literature although this experiment also explores the use of rhizobium inoculation as substitute for the N fertilization, obtaining a general reduction of plant growth. It is also important to keep in mind that the quantity of applied struvite is 2 g and 5 g for the proposed treatments. Rech et al., 2018 also discusses the low solubility of struvite compared to TSP, also mentioning a greater uptake of P by soybean and wheat with struvite fertilization compared to the control treatment. Only S15 and S20 reach a similar P amount to the control in all plant organs. For this reason, a quantity between 15 and 20 g of struvite, a responsible irrigation management and growing successive crops with the same substrate constitutes the best option to grow a well-designed struvite bean crop cycle. Although the P uptake of the struvite fertilized treatments appears to be equal or rather smaller than the control treatment the production is greater for all treatment with more than 5 g of struvite.

In the literary review proposed by Ahmed et al., 2018 the increase of biomass and yield by plants fertilized with struvite can be related to the simultaneous dissolution of Mg and NH4+. Although the uptake of P is reported in this study the Mg and NH4+ concentration in the plant was not analysed. The Mg uptake has been reported to be strongly correlated with the given Mg in the struvite and can be pointed out as a possible source reason for greater growth and production .Worldwide, fresh water scarcity is increasing demand for water reuse in agriculture, and municipal wastewater is a common and widely available irrigation source . Currently, twenty-four countries permit food crop irrigation with treated municipal wastewater, and eight countries permit irrigation with raw, untreated wastewater . Irrigating food crops with municipal wastewater is not without risks to soil chemistry , soil quality , microbial communities , and plant productivity . Wastewater irrigation also increases the availability of anthropogenic organic chemical uptake to plants and subsequent human consumption . In the United States, treated municipal wastewater is used to irrigate agricultural crops for direct and indirect human consumption . Wastewater irrigation of food crops intended for direct human consumption is more stringently regulated, and the U.S. Environmental Protection Agency provides guidelines  although individual states issue permits for food crop irrigation . Current guidelines do not address non-regulated organic chemicals or chemicals pending regulation on the U.S. EPA Contaminant Candidate Lists . Critical knowledge gaps persist regarding exposure risks to humans consuming wastewater-irrigated food crops . Goodwin et al. reported that public acceptance of water reuse improves when public engagement about water reuse addresses crop safety, and developing frameworks for public health risk-based targets is the most frequently prioritized action item in the 2020 USEPA National Water Reuse Plan . Organic chemicals of concern  include regulated legacy pollutants, such as polycyclic aromatic hydrocarbons, pesticides, ebb and flow table industrial solvents, and ammunitions, and non-regulated chemicals including pharmaceuticals and personal care products, engineered nanomaterials, and perfluorinated compounds .

Recent studies have evaluated COC presence and distribution in plant tissues in wastewater irrigated food crops based on physio-chemical characteristics, plant physiology , and targeted quantification of specific COCs . Generally, COC concentrations were greater in plant roots than shoots and fruits . Plants exposed to COCs in hydroponic systems had greater COC concentrations in plant tissues than plant-soil systems due to COC sorption to soils and reduced bio-accessibility . The US EPA uses hydroponic studies to evaluate the uptake and distribution of various COCs such as pesticides, pesticide residues, and emerging contaminants . USEPA OCSPP 850.4800 method exposes target food crops to hydroponic solutions for two weeks to assess COC uptake to plants . Across varied chemical use categories, industrial/surfactants, pesticides, pharmaceuticals, and personal care COCs concentrations were greater in growth solutions than plant leaf or fruit tissues after exposure . Translocation factors were larger for leaf versus fruit tissues and clear trends were not apparent between log Kow and translocation factors. For these reviewed studies , COC concentrations in plant tissues were several orders of magnitude lower than published average daily intake values . Targeted hydroponic studies often address specific COCs within a chemical use category or class and are not holistic assessments of chemical mixtures present . Fu et al. recommends that COCs detected in edible organs or roots of wastewater-irrigated food crops be prioritized for health risk assessments and that non-targeted and suspect screening analyses high resolution mass spectrometry are needed to refine and resolve COC presence and metabolism by plants to provide a more holistic human exposure assessment of chemical mixtures in irrigated food crops. Recent studies have used NTA HRMS to evaluate organic COCs in various water sources including surface waters , ground waters , and municipal waste waters .

Municipal wastewater can contain thousands of chemical features of which only a small portion are tentatively-identified chemicals . Few studies have used NTA and SSA HRMS for COC evaluation in plants or for the evaluation of food crops irrigated with municipal wastewater . This study compared NTA and SSA HRMS analyses of soybean tissues and seed produced in hydroponic solutions of different irrigation sources from an agricultural watershed to assess the diversity and chemical category use of COC uptake from varied irrigation sources. One hydroponic study followed USEPA OCSPP 850.4800 method for 14 days while a second study continued for 56 days to produce fruit and seed. NTA and SSA HRMS results were compared to HRMS results from passive samplers that were incubated for 14 days in the same irrigation sources. We used soybean, Glycine max L., as a model food crop and collected secondary-treated wastewater from a municipal land treatment site , surface waters , and ground water from the LTS and off-site of the LTS in an agricultural watershed. Municipal tap water amended with Ionic Grow™ was used as a reference treatment. We hypothesized that more chemical features and identifiable COCs would be detected in hydroponic soybeans grown in municipal wastewater than other watershed irrigation sources or the reference municipal drinking water. We expected comparable number and abundance of chemical features and tentatively identified COCs in the passive samplers versus extracted irrigation sources and extracted plant tissues.

Whilst the increase in ABA was not replicated in soil-based experiments, we did observe an increase in biological activity  when both earthworms and plants were present. This could indicate a potential synergistic relationship between plants, soil microbes and earthworms, which could be further investigated using the developed methods. Differences between the results of the hydroponic and soilexperiments may in part be due to the use of different earthworm species. E. fetida are litter feeders and L. terrestris are an anecic  species, and consequently they will interact with the soil differently. Differences between the two species in terms of e.g. sensitivity to toxicants  and biochemistry  in addition to behavioural differences are well established in the literature. The additional complexity of a soil matrix compared to hydroponic solutions will inevitably increase associated difficulties in the extraction. It is also possible that increased biological activity in soils compared to hydroponic experiments leads to degradation or conversion of phytohormones during extraction. There is therefore scope to improve the extraction method to achieve better recovery, allowing the observation of more subtle changes in phytohormone concentrations within soils.Perfluoroalkyl acids  have been detected ubiquitously in water , biota and the atmosphere as well as in humanblood serum and breast milk . They have known and suspected toxic effects , and human exposure occurs via food . In response to concerns about these chemicals, the European Food Safety Authority established tolerable daily intakes for perfluorooctanoic acid and perfluorooctane sulfonic acid,and they have recently presented a proposal to add perfluorononanoic acid and perfluorohexane sulfonic acid while reducing the TDI for the sum of all four . To ensure that the TDIs are not exceeded, we must understand the sources of PFAAs in food. Crops are one possible vector for PFAAs into the food supply.This work aims to further our understanding of how PFAAs are transferred from soils into crops. Plant uptake of PFAAs via the roots has been studied using several experimental designs.

The first studies published were soil based experiments. Stahl et al. and Lechner et al. showed that the concentration of PFOA and PFOS in several crops was linearly proportional to the concentration in the soil in which they were grown. Since then there have been several reports of uptake of a broad spectrum of PFAAs in vegetation growing in biosolids-amended soils. They show that the length of the per- fluoroalkyl chain is the dominant variable influencing PFAA uptake in foliage. Foliage concentration factors  are negatively correlated with chain length . For grasses, vertical grow tables an average decrease in FCF of 0.24 log units per CF2 group was observed , while for lettuce and tomato plants the average decrease was 0.3 log units per CF2 group . Regarding PFAA accumulation in root tissue, a much weaker influence of chain length has been observed. For instance, the variation in root concentration factors  for C5eC10 perfluoroalkyl carboxylic acids  was just 0.5 log units for radish, celery, tomato and pea . A similarly small variation was found between PFHxA, PFOA, PFBS, PFHxS and PFOS in wheat  . In contrast, root concentration factors in chicory showed a pronounced dependence on the chain length, suggesting that root accumulation is influenced by species and soil type . Hydroponic experiments provide an opportunity to obtain a more systematic understanding of contaminant accumulation in plants. For instance, a hydroponic experiment was used to assess the influence of different metabolic inhibitors on the uptake of PFOA and PFOS in maize shoots . The influence of pH on PFAA uptake into maize roots was also elucidated in a hydroponic experiment, showing no effect in a pH range of 5e7 for nine of the ten PFAAs studied . A hydroponic study was used to explore the effect of temperature and salinity on PFAA uptake in wheat, identifying a positive effect for both, which was attributed to increased evapotranspiration . Hydroponic experiments have also been used to study how perfluoroalkyl chain length influences uptake in plants. PFAAs with perfluoroalkyl chain lengths ranging from 3 to 13 were all transferred via the roots to the plant foliage in lettuce, tomato, cabbage and zucchini . Transpiration stream concentration factors  for C4eC10 PFAAs ranged over just a factor of two for three of the four species. Relatively high TSCFs of 0.05e0.8 showed that the PFAAs were clearly able to cross the Casparian strip and plasma membranes that prevent the passive entry of many polar molecules into the vascular tissue of the root . A weak influence of chain length on TSCF was also observed in grass . Hydroponic studies have also been used to study PFAA uptake into roots. In lettuce, the root-nutrient solution concentration factor decreased with chain length for C4eC6 PFCAs before increasing by almost 3 orders of magnitude from PFHxA to PFUnA.

While the accumulation of the shorter chained compounds was explained by uptake with the transpiration stream, the uptake of the longer chained compounds was attributed to sorption to the surface tissue of the roots . Hydroponic experiments with tomato, cabbage and zucchini showed a strong positive relationship between root-hydroponic solution concentration factor and chain length for C4eC11 PFAAs, indicating that root-surface sorption was the dominant uptake mechanism for all of the PFAAs in these species . In detailed experiments with a hydroponic model plant system , Müller et al. also concluded that the root uptake of all but the shortest PFAAs was governed by sorption and observed that the dead roothydroponic solution concentration factor increased by almost 3 orders of magnitude from PFBA to PFOS. Comparing the results from hydroponic and soil experiments, there are clear differences in the chain length dependence of PFAA uptake. In foliage, the hydroponic studies show a weak dependence of uptake on chain length, while soil studies show a very strong dependence. The opposite is the case in roots; the hydroponic studies show a strong positive chain length dependence that is attributed to sorption to root surfaces, while the soil studies show a weak dependence. It is unclear what the reasons for these differences are, and how and to what extent findings from hydroponic studies can be transferred to natural soil systems. Sorption of PFAAs to soil solids is certainly an important factor, as this reduces the fraction of chemical available for uptake by the roots. To be able to sorb to the root surface or be taken up with the transpiration stream, the compounds first need to be present in pore water. Long chain compounds sorb strongly to the soil; hence, for a long chain PFAA much higher concentrations in soil are required to generate a given concentration in pore water than for short chain PFAAs . However, there may be other factors that affect the comparability of hydroponic and soil systems. For instance, some contaminants appear to be taken up through the action of root exudates , which would be highly diluted or not present under hydroponic conditions. Another possibility is that differences in the nature of root tissue when grown under hydroponic conditions influence PFAA uptake and translocation. The uptake of the PFAAs could also be influenced by other solutes present in the soil. To explore these questions, we conducted a lysimeter experiment in which lettuce was grown in soil containing PFAAs, and compared this with our previous hydroponic experiment conducted with the same plant species, chemicals, sample preparation and analysis. The lysimeter soil was spiked with 11 PFCAs and 2 perfluoroalkane sulfonates . Four lysimeters were used, each with a different spiking level. At maturity the lettuce was harvested and the roots and leaves were analyzed separately.

Additionally, the PFAA concentrations in soil and pore water were determined. The measurement of concentrations in pore water facilitated comparison of this experiment with our earlier hydroponic greenhouse study, and thereby identification of differences in the uptake into roots and leaves between soil and hydroponic growth environments.The field experiment was conducted at the Fraunhofer Institute for Molecular Biology and Applied Ecology IME in Schmallenberg, Germany. Lettuce plants  were grown in 5 lysimeters, one containing soil with background concentrations of PFAAs , and 4 with intended concentrations of individual PFAAs in soil of 0.1 mg/kg, 1 mg/kg, 5 mg/kg and 10 mg/ kg . This compares with PFOA and PFOS concentrations of ~1 mg/kg measured in contaminated agricultural soil in Arnsberg, ~30 km from Schmallenberg . The results from the highest spiking level were not used because the lettuce plants were significantly smaller at the time of harvest than those growing in the lower exposure levels, indicating that PFAAs had phytotoxic effects . Phytotoxic effects of PFAAs have been reported elsewhere . Each lysimeter had a surface area of 1 m2 and a total depth of 60 cm. The lysimeters were each filled with ~450 kg sand  and ~450 kg of loamy sand . This resembled a typical soil from northwestern Germany. The soil used for the upper layer is available as a reference soil  from Fraunhofer IME . The spiking of the soil was done stepwise. First a stock solution was prepared containing all PFAAs in methanol. With this stock solution 2 kg of soil were spiked. Afterwards the 2 kg spiked soil was mixed with approximately 90 kg of soil in a concrete mixer to achieve the desired concentration. This was repeated 5 times for each layer in each lysimeter. Samples were taken from each batch and combined to determine the initial PFAA concentration in the soil of each lysimeter. The lettuce plants were pre-grown in a greenhouse for 2 weeks in non-spiked soil before they were transferred to the lysimeters. Within one week of preparing the spiked soil, 20 lettuce seedlings were put in each lysimeter . The seedlings were watered after planting, and kept humid by rain events until harvest with supplementary watering when needed . After 72 days the lettuce plants were harvested . The plants were divided into roots and foliage, packed in freezer bags and stored at  20  C until analysis. Soil samples were taken with a soil corer when the plants were harvested. The soil core, which was taken from the top to the bottom of the lysimeter,flower pot was divided between the upper and lower soil layers, and the soil was packed in freezer bags and stored at  20  C for later separation of pore water and analysis.Before homogenization with a household blender  the roots were rinsed with demineralized water to wash off residual soil and then carefully dried superficially with paper towels. As no residual soil was visibly apparent on the leaf samples, no cleaning was performed. The extraction method used is based on the modification Vestergren et al.  proposed for the method published by Hansen et al. . Briefly, 10 g of the homogenate were weighed into a 50 mL PP tube and spiked with mass-labeled surrogate standards.

After adding 5 mL of 0.4 M NaOH solution and vortexmixing, the samples were left in the refrigerator  over night to allow the internal standards to distribute in the slurry. Next, 4 mL of 0.5 M tetrabutylammonium hydrogensulfate solution and 5 mL of a carbonate buffer  were added to the samples and thoroughly mixed. After adding 10 mL MTBE and vortex-mixing for 1 min the samples were sonicated for 10 min. Phase separation was achieved by centrifuging for 10 min at 3000 rpm. The MTBE phase was transferred to a new 50 mL PP tube and the extraction repeated two times. The extracts were combined and concentrated to approximately 2 mL using a Rapidvap . After adding 1 g of sodium sulfate to Florisil SPE-cartridges to remove any remaining water in the extracts, the cartridges were conditioned with 10 mL MeOH and 10 mL MTBE before they were loaded with the extract. The elution of the non-polar matrix was done with 10 mL MTBE before the target compounds were washed off the cartridge with 10 mL MeOH/MTBE . This extract was again evaporated to 1 mL final volume. An additional clean-up step following the Powley method with ENVI-Carb  was added when the final extract was still strongly colored.

Plain film radiography is an economical method of visualising radio-opaque objects, but computed tomography still remains the gold standard of initial imaging. However, in cases of organic foreign bodies, magnetic resonance imaging  may be required, as wooden objects tend to mimic air on standard CT window settings. Although complications associated with intra-orbital trauma include visual loss, orbital inflammation, secondary infection, osteomyelitis, ptosis and even brain abscess, in rare cases, no visual morbidity occurs. In this case, although the foreign body was there for more than a week, the patient did not have any associated orbital cellulitis. This may be due to the inert nature of the foreign body, unlike in cases of intraorbital organic foreign bodies. Interestingly, the kind of injury sustained in this patient, i.e. a foreign body embedded in the inferior orbital rim and causing a fracture, is usually associated with high velocity injuries and thus greater visual disability. Our patient was fortunate as his vision was still 6/6 in both eyes, and he did not develop any long term ocular complications. Patients with suspected intraorbital foreign body are usually started on systemic antibiotics because of the high incidence of secondary orbital infections. Anaerobic coverage should be provided where the foreign body is suspected to be composed of organic material. Our patient was started on amoxicillin clavulanate for broad spectrum Gram-positive and Gram-negative coverage, and metronidazole for anaerobic coverage. Management of the intraorbital foreign body depends on clinical presentation, nature and the location of the foreign body in the orbit. Because foreign bodies can cause irritation of the mucosa that can be result in sinusitis, the removal of all foreign bodies is generally recommended, even when they do not produce symptoms. In rare cases, the foreign body may extrude spontaneously, but in general, the decision of whether to remove an intraorbital foreign body has to be made by the co-managing team. Presentation of the patient with visual compromise, ptosis, diplopia, orbital inflam-mation or infection mandates urgent removal.

Likewise, surgical removal is indicated for all organic foreign bodies because of the high rate of secondary complications. However, surgical exploration in case of inorganic foreign bodies depends on their location and the potential complications if left in place. For instance, 25 liter pot the access to anteriorly located intraorbital foreign bodies is relatively simple, and thus these should be removed. In posteriorly located foreign bodies, however, the risk of surgery may outweigh the benefits, so in the absence of significant orbital complications, these should be left untouched.With an estimated 50 million infections per year across many countries, Dengue is now recognized as one of the major public health problems worldwide. It is a mosquito-borne illness belonging to the genus flavivirus and consisting of 4 distinct serotypes, namely DENV-1, DENV-2, DENV-3 and DENV-4 . In majority of the cases, the illness is self-limiting with mild symptoms such as fever, rash and joint pain . However, this may predispose to a severe form  with infection with a different serotype . Today, dengue is endemic in more than 100 countries across Asia, Africa, America, Eastern Mediterranean, and West Pacific. Central to this is the enlarging habitat of its vectors, Aedes aegypti and Aedes albopictus. Aedes aegypti in particular, is highly adaptive in crowded areas; hence epidemics have been seen in cities with un-planned urbanization and overcrowding. Pakistan also had its share of dengue outbreaks in the recent years owing to the factors mentioned above. Epidemics have been reported especially in urban areas of Karachi and Lahore; situation worsening especially after monsoonal rains and floods. In October 2010, a total of 1809 cases were suspected out which 881 cases were confirmed of Dengue infection. In 2011, worst outbreak occurred in the country when more than 14,000 people were affected with dengue with over 300 deaths. Considering the current situation of Dengue virus and unavailability of data in Pakistan urgent attention and oversight is required to ensure effective preventive and curative program development. The objective of this study was to estimate the proportion of Dengue virus specific IgG ELISA among asymptomatic children between the ages of 1 year to 15 years, residing in an urban population of Karachi. When re-infected this population would potentially be at a higher risk of developing severe forms of dengue hemorrhagic fever. A cross sectional survey was conducted from September 2011 to February 2012 to estimate the prevalence of dengue virus. The study cohort consisted of children between one to 15 years of age. The study participants were stratified by geographical zone and age group. There were four zones  in the Garden area. The participants were divided into three age groups of 1 – 5 years, 6 – 10 years and 11 – 15 years. Seventy five children were included from each age group in each zone to ensure that the sample was representative not only 1 zone that why each zone was divided equally. Thus a total of 900 children were enrolled in the study and for the selection of respondents systematic random sampling technique was used.

After taking written consent from the parents/guardians, data was collected by research medical officers using a questionnaire, specially prepared for this survey. Information was collected on household socioeconomic status, medical history of febrile episodes including previous dengue infection followed by general clinical examination. Anthropometry height  and weight  was also performed. Blood samples were collected from the subjects and sent to Research Laboratory, Aga Khan University, Pakistan for determining complete blood counts and serum IgG antibodies for Dengue. Complete blood counts were tested using automated hematology analyzer .Dengue IgG antibodies was determined by Enzyme Linked ImmunoSorbent Assay , using Pan Bio Kits . Our study indicated that 46% of the population had been infected with dengue virus, making them susceptible to severe forms of dengue fever. To date, no study of this sort had been conducted from Karachi, Pakistan. Our study showed that Dengue IgG was found more in elderly children . This finding has also been reported by other researchers in their settings. Our study also showed greater preponderance of dengue IgG antibodies in males compared to females. Where reports suggest no significant differences associated with sex that might be different from Pakistan’s perspective owing to the fact that majority of the females remain indoors while males spend their maximum time outside. As mentioned previously, the dengue vectors are highly adaptable to any environment, hence it is probable for male children of such ages to become exposed to its habitat more often and contracting the virus. In our study, analysis revealed dengue IgG positivity to be more among lowest categories of socioeconomic position, comprising of 19% of the studied population. This was consistent with the study reported from Brazil. In our study, the finding was perhaps expected as Garden is a modern urban area with high rise buildings and inhabited by affluent communities.Employing strategies for water purification was also found to be important in the study, indicating a more likelihood to prior dengue infection in absence of water purification. In our analyses, 39% reported to purify water for consumption, using methods such boiling , filtering  and chlorination . It can be conceived that untreated water would be the possible niche for the Aedes mosquitoes to breed and multiply. Unique in this study is the positive association of stunting with IgG positivity . Our analysis also revealed a lesser likelihood of IgG positivity in presence of anemia and thrombocytopenia. These 3 conditions are pretty prevalent in this part of the world, each clinical correlate limiting us to offer any interpretation to its significance with IgG positivity. Some limitations are to note in this study. For instance we opted to collect information from a relatively affluent community of Karachi. Though previous studies on Dengue from around the world have indicated Dengue to be a threat for the urban areas, including squatter settlements would have provided a comparative picture showing proportional associations of positive IgG with overcrowding, sanitation and presence of domestic animals. The important and interesting aspect is to assess the serotype of the most prevalent dengue virus in these settings, as limited literature suggests DENV-2 and DENV-3 to be most prevailing in Pakistan.Lead is a naturally occurring metal that is used in many industrial processes, some of which lead to contamination of urban environments.

Lead deposition in urban areas is often atmospheric, originating from manufacturing, especially battery production, as well as in gasoline, and paint residues. Lead toxicities in people result in developmental, cognitive, motor, behavioral and physical injury, and for this reason, there is no acceptable lead level in the human system. In urban environments, lead may enter soils through atmospheric deposition, from dust near roadways, and from paint chips near buildings. Food grown in lead contaminated soils may be ingested, entering the consumer either directlyas transported particles containing lead or by absorption of lead salts in the crop consumed. Lead is persistent in soil. Since food insecurity is highest in large cities, recent efforts to produce food locally and in community gardens has increased, and lead ingestion must be examined carefully in urban food production systems. Attempts to alleviate food insecurity of impoverished citizens in cities by “guerrilla farming” activists may be putting consumers of such foods at risk, especially when farming on “Brownfield” sites previously contaminated with lead. Thus, those attempting food production in cities may be at risk for lead consumption and poisoning. Radish , a root vegetable, commonly grown worldwide, is consumed raw, raspberry cultivation pot as well as in a variety of preparations. Because radish grows rapidly from seed, it is preferred in school gardens where children can observe its rapid growth and development. All parts of radish are consumed, including foliage, the fleshy tap root, seed oils, and the immature seed pods. Ten species of radish are described in literature. The ability of globe radish  to absorb lead is known, and some varieties are “hyper-accumulators”. The variability of lead uptake in radish cultivars is not known. Lead salts occur in soil as oxides of metallic Pb or as salts that result from chemical reactions that may occur in soil. The solubility of lead salts in water is quite variable, from highly soluble lead nitrate  to practically insoluble lead sulfate . Lead is a divalent cation and is easily adsorbed onto clay colloids, or other cation exchange sites including organic matter, when it is in a soluble ionic state. Since lead reacts with oxygen and many other elements, there are likely many possible lead compounds and intermediates which may be present in contaminated soils.

In this study we present lead uptake data by five cultivars of radish growing in soils of two different textures, using two different lead salts as the lead sources.Soil was collected from 211 West Foothill Blvd, Claremont, CA , USA, which was a site known to be contaminated with lead. Multiple samples were collected along three linear transects of the site equidistant within a plot measuring 45 × 45 m. combined and homogenized. Samples were collected from the upper 20 cm of soil in spring of 2013. The site soil was dried, ground and sieved at the University of California Agriculture and Natural Resources lab  and analyzed for lead content using a nitric acid digest/extraction and detection by inductively coupled atomic plasma emission spectrometry  following procedures of Sah and Miller & Meyer and Keliher. Soil was passed through a 2 mm screen to remove rock and other large particles and blended with washed sand in a 3:1  ratio to improve bulk density for container culture of radish seedlings. Urea  was added at a rate of 1.25 g per 5” container containing 1.54 kg of blended sand and site soil to provide nitrogen for seedling growth. Five varieties of radish and one of mustard were obtained from High Mowing Organic Seeds  and seeded 1gm of each variety in each experimental unit . The study included radish cultivars “Cherry Belle”, “White Beauty”, “Purple Plum”, “French Breakfast” and “Rudolf” as well as the known lead hyper-accumulator Red Giant Mustard  Brassica juncea L. As a control, one of the radish cultivars  and RGM were grown in soil-less media composed of peat moss and sand  and fertilized with urea as above.

A growing part of and Product & Market Services  and FloraHolland Connect’s services is custom advice. Moreover, the flowers auctioned in FloraHoolland are not only limited to productsin Netherlands but also from Israel, Kenya, Colombia and etc. Whereas in KIFA, the flowers sold are mainly supplied by local growers. And growers can freely choose their dealing location and method, for example, many growers trade their products at Dounan Flower Market in wholesale method. In addition, small-scale production results in periodic intermittent supply. 5) Destination of sale. FloraHolland wants to maintain and reinforce FloraHolland’s position as the marketplace for European flower sales, maintaining its central position in the world’s leading areas for greenhouse horticulture is also its long development strategy. KIFA is one of biggest trade center in China, its buyers are almost from all of Chinese inner large-medium-scale cities. A small quantity of buyers is from Hongkong. Russia and Thailand sometimes take part in auction. 6) Logistics systems. FloraHolland has already established integrated systems for logistics, including inner logistical systems, logistical resources, and international logistical support. RFID, uniformed trolley resource, cool chain, potted-plant distribution, and air freight is being developed for supply and distribution chain from farm to auction market and from auction market to distribution at FloraHolland. Due to the restriction of external environments, KIFA now applies itself to establish collecting center in main planting area to decrease supplier’s logistics costs due to scale economies and re-design internal logistics distribution mode to improve allocation efficiency. 7) Standardization. The decoding standards of varieties, products, grades, and qualities have been built for many years at FloraHolland.

After merged in Jan. 2008, it will more rapidly achieve standardization in the whole chain of production and supply. FloraHolland have decided that all the trolleys, all the purchase and sales invoicing will be carried out the same standard for various locations and FloraHolland connect. Owing to standard scarcity of agricultural production in China, KIFA is now hammering at own intellectual property right of cut flowers. The past two years were turbulent because of financial crisis. Although sales of flowers and plants were generally not very sensitive to economic recessions,barley fodder system growth market shrank as a result of currency problems. FloraHolland is also striving to support its clients and members do business optimally in the current difficult circumstances. The number of suppliers and traders of FloraHolland did not grow in 2007. Turnover increased by 4.4%. This resulted in a total turnover of €3,892 million. The increase can be attributed to a 3.8% positive price trend and an increase in volume of 1% . Commission revenue just increased 0.4%, as a result of a reduced commission for the auction clock. The scale of suppliers and traders for FloraHolland has improved. These may be private companies and cooperative ventures, which operated as a major player in the market and were well placed to innovate. Number of employees of FloraHolland in 2007 deceased by 0.46%, at the same time, the productivity had 2.5% increase which ensured the volume increase. The year 2008 for China is a significant one because Peking Olympic Games was successfully held in Peking. So KIFA predicted sales, price and supply of cut flowers would have increased rapidly. But in fact sales, price and supply of cut flowers in China did not grow in 2008. Despite the difficult economic situation, 2008 ended with a hugely positive turnover for KIFA because of new business model. Annual turnover of KIFA increased by 53%, it resulted in a total of ￥163 million. The increase can be owed to an increase in volume 60%. Commission revenue increased by 53%, it resulted in a total of ￥16.4 million, which it is the first time that the revenue exceed the general costs . The number of suppliers and trades increased by 16% and 20% individually, as a result of the best price, the reliable quality, the decreased costs, the sufficient information and the increasing service level. The average number of transactions per day increased by 62% and the number of employees increased by 31%, it resulted in 60% increase in productivity in KIFA. 2008 was crucial and successful done one for KIFA, including operationally, commercially and financially.

However, lack of trading location  is a limitation to increasing the product supply. Considering the product category, it is difficult for KIFA to meet the buyers’ requirement by auctioning certain kinds of cut flowers while the products sold in FloraHolland cover almost all types of flowers and pot plants. The commission fee is also a noteworthy point. The commission rate in KIFA is 10.11% out of annual turnover, 8.65%greater than the commission rate in FloraHolland. Such a high commission is one of the factors that buyers and suppliers won’t choose the auction as their transaction mode.The sales of floriculture products for FloraHolland were a great success in 2007. Cut flowers, indoor plants and outdoor plants increased 1.74%, 8.78% and 9.54% individually . Exports from the Netherlands grew by 4.4%, thanks to the growth in Eastern Europe, France, the United Kingdom and Ireland. One attentive trend in FloraHolland is that sales through by connect had a great increase by 11.4%. Remote buying  has grown enormously in the past few years. Deals do not only buy in the auction room but also via an internet connection which means the location can be anywhere in the world. Another important fact is that the price of outdoor plants and indoor plants sold by connection is higher than by auction, which is different fact with the conclusion of Koppius et al. . From Table 3, we can also see that the revenue of selling indoor plants and outdoor plants is very large, about 38.5% out of total turnover. That means it is profitable not only through cut flower sales but also through indoor plants and outdoor plants sales. Although the sales of cut flowers for KIFA were a great increase in 2008, an important trend is that the ratio of bidding failure is increased. KIFA views this phenomenon in a positive sight. It means that the lower quality and outdated product should be washed out from the market. But on the other hand, it will depress the confidence of Chinese growers. Another difficulty for KIFA is that the batch size of cut flowers is also small at 180 units, at the same time, FloraHolland at 1800 units. Improving batch size of growers is a long-term and difficult task. Although auction is an old-fashioned deal method, it remains a strong selling instrument in foreign countries. Now FloraHolland is striving to intermediary services in direct transactions via the intermediary organization FloraHolland connect. But in China auction method emerged among some regions just in recent ten years, the cultivation of auction thought is a long-term process for growers and buyers.

Most of fresh agricultural auction markets in China were shutdown in past few years due to lower revenue. Through the comparison of operational goals and performances, we conclude that five operational strategy’s emphasis for developing Chinese flower auction markets as follows: 1) Transit of service strategies. Changing service thought is an important factor of Chinese flower auction markets. First of all, the auction market is not only the location for providing auction transaction, but an integral service provider for transaction, balance, logistics, information and direct sales. Second, providing customized service is crucial to keep participants loyal, so measures must be taken to decrease participants’ transaction costs to guarantee that growers and buyers choose auction as public platform for trade, such as providing various trade mode , excellent logistics and online payment. Finally, the auction market must be the knowledge center for participants. It can provide information on services and the very latest products, trends and sales concepts, so it can help participants to make their decisions. 2) Cultivation of participants’ network. Constructing participants’ network is a long-term and difficult process. The auction market must seek to achieve the highest possible price at the lowest possible expense for all members. The participants’ network is the best important assets for all of auction markets. As a result, it is very important to provide convenience, laborsaving, and happiness services for all members. An obvious trend is a growth in large scale flower and plant nurseries in China because of scale economies. The increases in scale take place predominantly through acquisition. The market may stimulate this and endeavor to increase the return because it is helpful to extend participants’ network. 3) Establishing standardization. Compared to traditional firsthand market, the auction market can provide uniform quality standard. Product quality is a high priority for auction market. The auction organization would offer the opportunity to more rapidly achieve standardization in the chain of production and supply. Doing this could greatly decrease the intermediate links and improve trading efficiency.

The standards of varieties, products, grades, and qualities are the first of all for Chinese auction market, which is the basis for well-doing operation. Owing to scarcity of fresh agricultural product standard, establishing standard is a difficult task for Chinese auction markets. 4) Clever mechanism design and avoiding some factors influencing successful auction. Clever mechanism designs are only very occasionally among the main keys to an auction’s success. Much more often, the keys are to keep the costs of bidding low, encourage the right participants to participate, hydroponic barley fodder system and ensure the integrity of the process. Some other factors are more important for Chinese auction market, such as setting right reservation price and commission rate, building clever disposal mechanism for lodge and bidding failure, and developing agent organizations for the small-medium growers and buyers. 5) Improving on operational performance continuously. The measurements must be brought into auction organization’s eyes, such as saving general costs for auction market, improving work efficiency, turnover, and service level, and increasing revenue and value added service. All these measurements require technology innovation continuously. Remote supply, remote buying, image auctioning, online sales systems, and direct sales, all of these new business models should be put into use through technology innovation. Rice  is the most important cereal crop in the world and it is the primary source of food and calories for about half of mankind. More than 75% of the annual rice supply comes from 79 million hectares of irrigated paddy land. Irrigation is an important practice in agriculture, the competition for fresh water in the development of urbanization, industry, leisure, and agriculture causes the decline of fresh water for irrigation. Water scarcity is a severe environmental limitation to plant productivity. Drought induced loss in crop yield may exceeds loses from all other causes, since both the severity and duration of the stress are critical.

Stress has been define as “any environmental factor capable of inducing a potentially injurious strain in plants”. Water is a major constituent of tissue, a reagent in chemical reaction, a solvent for and mode of translocation for metabolites and minerals within plant and is essential for cell enlargement through increasing turgor pressure. With the occurrence of water deficits many of the physiological processes associated with growth are affected and under severe deficits, death of plants may result. The effect of water stress may vary with the variety, degree and duration of water stress and the growth stage of the rice crop. Water stress during vegetative stage reduces plant height, tiller number and leaf area. However, the effect during this stage varies with the severity of stress and age of the crop. Long duration varieties cause less yield damage than short duration varieties as long vegetative period could help the plant to recover when water stress is relieved. Leaf expansion during vegetative stage is very sensitive to water stress. Cell enlargement requires turgor to extend the cell wall and a gradient in water potential to bring water into the enlarging cell. Thus water stress decreases leaf area which reduces the intercepted solar radiation. Rice leaves in general have a very high transpiration rate thus under high radiation levels rice plant may suffer due to mid day wilting. Rice plant can transpire its potential rate even when soil moisture was around field capacity.